A linear GaN UHF SSPA with record high efficiency

This paper discusses a highly efficient linear UHF solid state power amplifier (SSPA) developed for avionics and space applications. Predistortion linearization combined with high-voltage gallium nitride (GaN) FET technology allows the simultaneous achievement of both linearity and record high linear efficiency (70%). This amplifier will produce over 100 W of linear output power as well as a power added efficiency (PAE) at saturation approaching 90 percent. This paper describes the power amplifier design approach and presents measured test data.